Investigation of the structural distortion in FeSe x crystals by X-ray absorption near edge structures (XANES) spectroscopy

Abstract: Crystals of the new superconductor FeSe were investigated by X-ray absorption near edge structures spectroscopy (XANES) in the temperature range 300–77K. Crystals with Se content varying from x=1–0.8 were used. The Fe K-edge spectra show a structure distortion and increase in hole content as x decreases. The Fe K-edge spectra also show changes when the crystals are cooled to 100K which may be related to the orthorhombic distortion reported in these crystals. The data is examined in conjunction with XRD measurements on the crystals to seek a correlation. [Copyright &y& Elsevier]